Charles f



" UNITED STATES PATENT QFFICE.

7, CHARLES FQSPICKER, OF NEW YORK, N. Y. I

Specification forming partof Letters Patent No. 3,835ydated J one 24, 1844.

To all whom' it may comm:

Be it known that I, CHARLES F. SPIcKEn, )f the city, county, and State of New York, have invented a new Method of .Ooloring and Hardening Wood-and Preserving it from Denay, of whichthe following is a specification.

The substance used to produce the chemical,

change in wood, which is the object of this process, is tannin or tannic acid, which hasproperties adapted to condense and harden the fibrous structure of wood, and thus to make it more susceptible of a polish, as well as to preserve it from spontaneous decay and fromthe action of air. and water and other exterual agents ofdecomposition. Although these properties particularly that 'of preserving wood from decay, have incidentally come undcrthe observation of chemists, yet little or no practical use has been made of this material for such purposes, by reason of the ditficult-y and expense of applying it; and my invention consistsin a method of application by which it is made available for 'cotnmonuse.

. To impregnate wood in large masses and throughout its whole thickness with tannin or tannic acid, and combine the same chemicallly therewith, so that water cannot extract.

it, and together therewith to infnseacoloring matter or material that shall not be too expensive for use, and thoroughly incorporate the same with the wood, so as to make a permanent and uniform color,it is necessary with the extract of bark or other solution of tannin or tauicacid, combined with the coloring-matter, to use a strong solution of caustic potas'sa or soda, or even carbonate of potassa or soda, which, by momentarily softening the vegetable .fiber, facilitatesthe mechanical passage of the fluid through the whole substance ot'the wood, and increases at the same time the chemical aflinity of both substanceslfor each other.

. The coloring substance in this proccss, when any other is required than what is innatural combination with the tannin, may he any cheap vegetable color, and it does not require the more expensive mineral colors which have heretofore been supposed to be the only colors that could be used for such a purpose.

The solution of caustic putassa or soda is prepared with caustic limcin the manner that soapboilers make theirlye. In thissolutiou oak-bark is soaked for a length of time, or even boiled till all its virtue is extracted; but instead ot oak-burk,theextractothemlock,terra;ja.ponica, logwood, Brazil wood, or suinac may be used, and in fact all substances which consist of tannin or tanic acid or contain a great proportion thereof. Proportions, six pounds of oak bark, five pouuds'of potash, ten gallons of water. The coloring-matter, of course, to be. of such strength, and proportion aswill be suitable for the shade of color which is desired,

and as to which no particular directions are The solution (of both substances) is.

required. then putinto tanks or reservoirs, and the wood, in the shape of planks or timber, put into it, where it is left to soak for from two to four weeks, until, by specimens taken out, it is shown that the mass of the wood is incorporated with the tanniu or tannic acid. The

wood may be used seasoned'or unseasoued. It

isthen taken out and left to dry for a week, and then put into clear water to extract the potash or soda. It may even be boiled then withontextractingthetannin. Thewood may be boiled also at first in the solution of these substanccsabove mentioned, which does not produce, however, such fine coloring: Before; the wood is put'into the clear water it is well, though not necessary, to steam it, which seems to assist in fixing the coloring-matter. During the time the wood is being driedit is necessary to press it from time to time,eith'er by heavy weights or in a common press, to pre vent warping.

The process of impregnating the wood may be shortened by pressure from a hydraulic press or steam upon the tlhid in which the wood issoaking. To give the wood a darker .color it is, after being taken from the first vat or reservoir, put into asolution of sulphate'ofi iron or copperas, corroded lnthe air till it is darkened throughout, and then put intoclear water to extract the sulphate of potassa or soda. To vary the color other solutions of metallic salts maybe employed-such as sulphate of copper-after the wood has been tanned.-

The depth of the color bythe tanning process depends upon the strength of the solution of caustic potnssa or soda; Carbonate of potassa;

or soda yields a very light color. Focthe purnose of merely preserving timber the process may be shortened by boiling the wood in the tanning solution. v

The process above described'of using potash or soda in combination with tanninbr tannic acid may be advantageously applied to Menila, grass, hemp, and other fibrous materials used for cordage and shiprigging.

What I claim as my invention is The method of hardening andcoloring wood bydi'fl'using tannin-or tannicacill; together with vegetable colors, thl'OllghOlibthQ whole structme of the wood, and incorporating the some Manila grass and other articles used for cordage and ship-rigging. I

GHARLESYF. SPIGKER. Witnesses:

- AUG: W. R ADOLIFF, A..R. WADSWORTH. 

